Question about overloading .357 magnum - Page 2

rrruger · February 24, 2015, 05:12 PM

I shoot a GP100 which posters will tell you is as 'overbuilt' as it gets. Having said that, would I risk damage to a 600.00 gun for twenty bullets? Not likely!
You can borrow my bullet puller if you need to.

Peter M. Eick · February 26, 2015, 12:09 PM

Nah, The GP100 is a wimp compared to the 357 Redhawk.

That is some serious steel around a 357 round.

I bought several of these just for load development in the 357 Mag.

jimbob86 · February 26, 2015, 12:31 PM

Quote:

The GP100 is a wimp compared to the 357 Redhawk.

It may be built pretty stoutly, but judging form those primers, those mousephart loads you are shooting in it make that a pretty moot point!

**44 AMP** · February 26, 2015, 12:42 PM

I don't see where you get mousephart from those primers. Maybe they were, but you can't tell.

Use a strong enough gun, and loads that flow primers to the edge of the pocket in weaker guns look like normal moderate loads when shot in a "bank vault" thick kind of gun.

My "hell for stout" .357 is a S&W M28. I've shot loads from it where the primers say "hmm a little warm today.." and the same ammo from a model 19 the primers say "oh please, please DON'T DO THAT AGAIN!!" And cases had to be driven out with a rod and a mallet.

The big Ruger has even MORE steel than the M28.

Peter M. Eick · February 26, 2015, 09:18 PM

Actually he is right. They were "wimpy" loads for the gun. My standard 357 Magnum load is 15.0 grns of 2400 with a cci550 primer in starline brass and either an MBC or Lasercast 158 grn SWC.

That is 3/10's of grain below book max from the Lasercast manual book 1.

It is a wimpy load for a gun the size and strength of the Redhawk. My S&W N frames handle it well but it does get a bit snappy in the shorter barrel lengths.

I don't put those loads into my Python's anymore as I think it is more than the guns were meant to take. I have had too many cases of well sticky cases with 15 grns in the Python for comfort. No need to beat up a fine Python.

So it goes to show that reading primers does not tell the full tale on power and pressures. But I will agree with jimbob86, 15 grns is a "mousefart" load in 357 magnum. The real fun is when you get up higher than that.

(Where is that villainous laugh icon when you need it....)

And hats of to "Clark" for giving me the confidence to go well beyond published loads safely.

50 shots, 15 yrds, with the load quoted above in my 1939 Registered Magnum. It loves these type loads and shoots point of aim.

Clark · February 26, 2015, 10:01 PM

According to John Bercovitz in 1991, with a masters degree in mechanical engineering and a job at the Jet Propulsion Laboratory [JPL], the maximum load for 357 magnum is driven by the threshold of sticky cases.

https://groups.google.com/forum/?hl=...0/cBSU4bR2jz8J

Peter M. Eick · February 27, 2015, 11:06 AM

That post you (Clark) reference makes so much sense to me and convinced me to keep loading up for my big beasts of guns like the Redhawk or 38/44 Heavy Duty. Even the big S&W N frames can take "original" pressure 357 Magnums easily.

Today I think nothing of tossing 158 LSWC's out of my 8 3/8" pre-27s (S&W N frames) at 1500 FPS. They are a lot of fun to shoot at the range and quite enjoyable out of the big guns.

What I don't do is put those type of loads in my Pythons which is my only "small frame" 357 Magnum. I don't own any L or K or baby Rugers.

At the range, full (original) power 357 Magnums are impressive. I would hate to see someone touch one of them off in a house or car in a self defense situation.

I have wondered if I should get some 357 Magnum +P brass made up for original power level loads. This way I could differentiate them from the modern 357 Magnum loads which are really closer to 38/44 S&W Special High Speed loads from the 30's.

Currently I just put full power loads in red cases and SAAMI approved loads in blue cases so I keep them in the Pythons or my D-Framed Colts (38 Specials).

Lost Sheep · February 27, 2015, 12:44 PM

Welcome to the forum. Thanks for asking our advice.

Smokeless powders work within a limited band of pressures. Too low or too high are outside the predictable performance band.

Take 20 grains of powder, put is on a flat rock in a pile and light it. It will flame up for a second or so. It is burning at atmospheric pressure, 14.7 psi.

Take that same 20 grains of powder and put it inside a confined space. Pressure will build up, and as it does, the speed of the burning increases. This is the nature of smokeless powder. Enought pressure buildup before the propellant is all burned up and the speed of the burn approaches the speed of explosives. (Note that smokeless powder does not "explode", but simply burns very rapidly.)

Smokeless powders are formulated to burn predictably within a range of pressures (their "performance envelope"). Outside (either above or below) that pressure band, the burn rate is erratic and can result in any number of odd behavior and even ballisticians cannot predict with certainty what a low-pressure round will do, every time.

We do know that too much of a powder pretty reliably causes overpressure. The pressure/charge relationship goes non-linear in a hyperbolic way.

Now, about the bullet weight/propellant charge question:

Heavier bullet, lighter charge of the same propellant. To get the pressure up into the propellant's performace envelope with a light bullet (which moves down the barrel more easily, thus lowering pressure) requires more powder. A heavier bullet does not move so easily, thus a lighter charge of propellant has more resistance (inertia mostly, but friction with the barrel plays in, too) against which to build up pressure.

And, of course, the free volume os a factor. Less bullet in the case, more free space inside the case. More free space inside the case acts to slow the speed of pressure buildup. It takes 25 strokes of my brother's bicycle pump to increase pressure 1 psi in a car tire. 2 strokes will do that with a bicycle tire.

All this was mentioned by a few posts earlier, but I thought I would put my description in, too.

One thing not mentioned yet is that the powder itself is part of the load being sent down the barrel. The extra powder has mass and contributes to pressure buildup also. Though this is a minor factor, it does weigh in.

Where do you want to get your load data? Good sources are: The powder manufacturers' web sites. Published manuals. Equipment manufacturers' web sites. Casual sources from the internet or at the shooting range are good, but MUST be veted against more authoritative sources. There are some hare-brained loaders out there and innocent mistakes in communication can kill or injure you or a bystander. I ALWAYS compare load data from ANY source to at least one other source, even if both or all sources are authoritative. Cross-check everything is my advice.

I have several manuals, not only to compare their load data, but almost all loading manuals have descriptions of the loading process. These descriptions are written by different authors who emphasize differed points of the process and have different writing styles which may "speak" to you better. The ABC's of Reloading is republished every so often, so getting hold of a few old copies at your local library is likely to enhance your understanding of the process as well.

Good luck (but don't depend on luck)

Lost Sheep

p.s. Remember, your loading bench is an ammunition factory. Design your workflow and your quality control procedures just as carefully as you would if it were a million-dollar production facility.

February 26, 2015, 12:09 PM	#27
Peter M. Eick Senior Member Join Date: August 3, 1999 Location: Houston, Texas Posts: 2,991	Nah, The GP100 is a wimp compared to the 357 Redhawk. That is some serious steel around a 357 round. I bought several of these just for load development in the 357 Mag. __________________ 10mm and 357sig, the best things to come along since the 38 super!

February 26, 2015, 12:42 PM	#29
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,820	I don't see where you get mousephart from those primers. Maybe they were, but you can't tell. Use a strong enough gun, and loads that flow primers to the edge of the pocket in weaker guns look like normal moderate loads when shot in a "bank vault" thick kind of gun. My "hell for stout" .357 is a S&W M28. I've shot loads from it where the primers say "hmm a little warm today.." and the same ammo from a model 19 the primers say "oh please, please DON'T DO THAT AGAIN!!" And cases had to be driven out with a rod and a mallet. The big Ruger has even MORE steel than the M28. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

February 26, 2015, 09:18 PM	#30
Peter M. Eick Senior Member Join Date: August 3, 1999 Location: Houston, Texas Posts: 2,991	Actually he is right. They were "wimpy" loads for the gun. My standard 357 Magnum load is 15.0 grns of 2400 with a cci550 primer in starline brass and either an MBC or Lasercast 158 grn SWC. That is 3/10's of grain below book max from the Lasercast manual book 1. It is a wimpy load for a gun the size and strength of the Redhawk. My S&W N frames handle it well but it does get a bit snappy in the shorter barrel lengths. I don't put those loads into my Python's anymore as I think it is more than the guns were meant to take. I have had too many cases of well sticky cases with 15 grns in the Python for comfort. No need to beat up a fine Python. So it goes to show that reading primers does not tell the full tale on power and pressures. But I will agree with jimbob86, 15 grns is a "mousefart" load in 357 magnum. The real fun is when you get up higher than that. (Where is that villainous laugh icon when you need it....) And hats of to "Clark" for giving me the confidence to go well beyond published loads safely. 50 shots, 15 yrds, with the load quoted above in my 1939 Registered Magnum. It loves these type loads and shoots point of aim. __________________ 10mm and 357sig, the best things to come along since the 38 super!

February 26, 2015, 10:01 PM	#31
Clark Senior Member Join Date: December 4, 1999 Location: WA, the ever blue state Posts: 4,678	According to John Bercovitz in 1991, with a masters degree in mechanical engineering and a job at the Jet Propulsion Laboratory [JPL], the maximum load for 357 magnum is driven by the threshold of sticky cases. https://groups.google.com/forum/?hl=...0/cBSU4bR2jz8J __________________ The word 'forum" does not mean "not criticizing books." "Ad hominem fallacy" is not the same as point by point criticism of books. If you bought the book, and believe it all, it may FEEL like an ad hominem attack, but you might strive to accept other points of view may exist. Are we a nation of competing ideas, or a nation of forced conformity of thought?

February 27, 2015, 11:06 AM	#32
Peter M. Eick Senior Member Join Date: August 3, 1999 Location: Houston, Texas Posts: 2,991	That post you (Clark) reference makes so much sense to me and convinced me to keep loading up for my big beasts of guns like the Redhawk or 38/44 Heavy Duty. Even the big S&W N frames can take "original" pressure 357 Magnums easily. Today I think nothing of tossing 158 LSWC's out of my 8 3/8" pre-27s (S&W N frames) at 1500 FPS. They are a lot of fun to shoot at the range and quite enjoyable out of the big guns. What I don't do is put those type of loads in my Pythons which is my only "small frame" 357 Magnum. I don't own any L or K or baby Rugers. At the range, full (original) power 357 Magnums are impressive. I would hate to see someone touch one of them off in a house or car in a self defense situation. I have wondered if I should get some 357 Magnum +P brass made up for original power level loads. This way I could differentiate them from the modern 357 Magnum loads which are really closer to 38/44 S&W Special High Speed loads from the 30's. Currently I just put full power loads in red cases and SAAMI approved loads in blue cases so I keep them in the Pythons or my D-Framed Colts (38 Specials). __________________ 10mm and 357sig, the best things to come along since the 38 super!

February 24, 2015, 05:12 PM	#26
rrruger Senior Member Join Date: March 9, 2012 Posts: 153	I shoot a GP100 which posters will tell you is as 'overbuilt' as it gets. Having said that, would I risk damage to a 600.00 gun for twenty bullets? Not likely! You can borrow my bullet puller if you need to.

February 27, 2015, 12:44 PM	#33
Lost Sheep Senior Member Join Date: January 24, 2009 Location: Anchorage Alaska Posts: 3,341	BOTH low and high pressures are to be avoided Welcome to the forum. Thanks for asking our advice. Smokeless powders work within a limited band of pressures. Too low or too high are outside the predictable performance band. Take 20 grains of powder, put is on a flat rock in a pile and light it. It will flame up for a second or so. It is burning at atmospheric pressure, 14.7 psi. Take that same 20 grains of powder and put it inside a confined space. Pressure will build up, and as it does, the speed of the burning increases. This is the nature of smokeless powder. Enought pressure buildup before the propellant is all burned up and the speed of the burn approaches the speed of explosives. (Note that smokeless powder does not "explode", but simply burns very rapidly.) Smokeless powders are formulated to burn predictably within a range of pressures (their "performance envelope"). Outside (either above or below) that pressure band, the burn rate is erratic and can result in any number of odd behavior and even ballisticians cannot predict with certainty what a low-pressure round will do, every time. We do know that too much of a powder pretty reliably causes overpressure. The pressure/charge relationship goes non-linear in a hyperbolic way. Now, about the bullet weight/propellant charge question: Heavier bullet, lighter charge of the same propellant. To get the pressure up into the propellant's performace envelope with a light bullet (which moves down the barrel more easily, thus lowering pressure) requires more powder. A heavier bullet does not move so easily, thus a lighter charge of propellant has more resistance (inertia mostly, but friction with the barrel plays in, too) against which to build up pressure. And, of course, the free volume os a factor. Less bullet in the case, more free space inside the case. More free space inside the case acts to slow the speed of pressure buildup. It takes 25 strokes of my brother's bicycle pump to increase pressure 1 psi in a car tire. 2 strokes will do that with a bicycle tire. All this was mentioned by a few posts earlier, but I thought I would put my description in, too. One thing not mentioned yet is that the powder itself is part of the load being sent down the barrel. The extra powder has mass and contributes to pressure buildup also. Though this is a minor factor, it does weigh in. Where do you want to get your load data? Good sources are: The powder manufacturers' web sites. Published manuals. Equipment manufacturers' web sites. Casual sources from the internet or at the shooting range are good, but MUST be veted against more authoritative sources. There are some hare-brained loaders out there and innocent mistakes in communication can kill or injure you or a bystander. I ALWAYS compare load data from ANY source to at least one other source, even if both or all sources are authoritative. Cross-check everything is my advice. I have several manuals, not only to compare their load data, but almost all loading manuals have descriptions of the loading process. These descriptions are written by different authors who emphasize differed points of the process and have different writing styles which may "speak" to you better. The ABC's of Reloading is republished every so often, so getting hold of a few old copies at your local library is likely to enhance your understanding of the process as well. Good luck (but don't depend on luck) Lost Sheep p.s. Remember, your loading bench is an ammunition factory. Design your workflow and your quality control procedures just as carefully as you would if it were a million-dollar production facility.